This invention relates to vibratory feeders or conveyors, and more particularly, to a reversible or two-way vibratory feeder.
Two-way vibratory feeders or conveyors have substantial applications in a variety of fields. One typical application is in foundry operations. For example, castings may be delivered to the feeder at a location intermediate its ends and then the feeder is energized to feed the castings to one end or the other depending upon where it is desired to locate the castings. Typical two-way feeders include an elongated bed with an upwardly facing, generally horizontal conveying or feeding surface which terminates at opposite ends. The bed is supported on isolation springs adjacent the ends which in turn serve to mount the bed above the underlying terrain such as a floor in a factory building or the like.
Two motor and weight assemblies, which form vibration inducing systems, are secured to the bed generally centrally thereof. Each will typically include a squirrel cage motor having a rotary output shaft to which is secured in an eccentrically mounted weight. Springs in the form of plastic or fiberglass slats connect each of the motors to the bed.
Each of the vibration inducing systems is canted at approximately 45xc2x0 to the bed but in directions oppositely of one another. When it is desired to feed in one direction, one of the vibration inducing systems is energized while the other remains quiescent if the opposite direction of feeding is required, then the other vibration inducing system is energized while the first remains quiescent.
In many applications, it is not unusual that there is a considerable disparity between the amount of use of the two vibration inducing systems. If one system is used to the substantial exclusion of the other, so called xe2x80x9cfalse Brinnellingxe2x80x9d of the motor bearings on the unused system will occur as a result of the vibration imparted to the bed by the first system. Lubricant may be squeezed out of the bearings as a result and when the system is finally energized, it may fail relatively quickly as a result of bearing failure.
Moreover, in foundry applications, the bed typically will be formed of metal to stand up to the continued pounding of castings. In a prior art system such as described, vertical acceleration of the feeding surface during operation will typically exceed that of gravity. As a result, after the surface has reached its highest point of movement in a cycle of vibration, it will then be accelerated downwardly more rapidly than a casting or the like conveyed by the feeder in responding to gravity. The casting will be temporarily suspended above the conveying surface but will eventually collide with it as movement of the surface begins to reverse while the casting is being moved downwardly under the influence of gravity. The result is a noise producing impact of the casting upon the metal of which the conveying surface is formed and the noise level will typically be undesirably high.
It will also be appreciated that the provision of two vibration inducing systems in a single feeder or conveyor when only one is used at any given time adds considerably to the cost of the apparatus.
The present invention is directed to overcoming one or more of the above problems.
It is the principal object of the invention to provide a new and improved two-way or reversible vibratory feeder or conveyor. More specifically, it is an object of the invention to provide a vibratory feeder wherein the problem of premature bearing failure is eliminated, the noise produced during operation is substantially reduced, and the cost of construction is reduced by the elimination of many components heretofore believed required in a construction of such a vibratory feeder.
It is also a principal object of the invention to provide a new and improved vibratory feeder of extremely simplified construction to thereby reduce initial cost as well as ongoing maintenance requirements.
An exemplary embodiment of the invention achieves the foregoing objects in a vibratory feeder that includes a base. Means define an elongated, generally horizonal feeding surface which is spaced from the base and a rotatably mounted eccentric is journaled on the surface defining means and operable, when rotated, to impart vibration to the surface. An interconnection mounts the surface defining means to the base and consists essentially of a resilient element having one end connected to the surface defining means and an opposite end connected to the base. The resilient element has its ends on a generally horizonal axis and is of sufficient stiffness to prevent the axis from shifting from a generally horizontal position.
In a preferred embodiment, there is additionally included a reversible, rotary output motor for driving the eccentric. The motor, for one direction of rotation causes feeding in one direction on the surface defining means and for the other direction of rotation, causes feeding in the opposite direction on the surface defining means.
In a preferred embodiment, the surface defining means and the eccentric have a combined center of gravity and the generally horizontal axis extends through the combined surface of gravity.
In a preferred embodiment, there are at least two of the resilient elements, one on each side of the eccentric.
Preferably, the resilient elements are coil springs.
In another facet, the invention provides a vibratory feeder that includes a base along with means defining an elongated, generally horizontal feeding surface spaced from the base and a rotatably mounted eccentric journaled on the surface defining means and operable, when rotated, to impart vibration to the surface. The feeder further includes a pair of spaced, resilient elements located on a generally horizontal axis and connecting the surface defining means in the base. The resilient elements are of sufficient stiffness as to maintain a desired spacing between the surface defining means and constitute the sole means interconnecting the base and the surface defining means.
Preferably, the eccentric comprises a weight mounted on the output shaft of a reversible motor.
In a preferred embodiment, each resilient element comprises at least two horizontally elongated, coil springs.
By still another definition, an exemplary embodiment of the invention is a two-way vibratory feeder that includes a base, a horizontally elongated feeder having an upwardly facing feeding surface and opposed ends, and a reversible motor having a rotary output shaft and generally centrally mounted between the ends of the feeder with the output shaft being generally horizonal and transverse to the direction of elongation of the feeder. At least one weight is eccentrically mounted on the output shaft and is rotatable therewith for either direction of rotation thereof. A support assembly is provided for connecting the feeder to the base and consists essentially of two spaced horizontally disposed coil springs, one on each side of the output shaft, each such spring having two ends with one end mounted on the base and the other end mounted to the feeder.
According to one embodiment, the feeder, the motor and the weight have a combined center of gravity and the springs are located on a horizontal axis that extends through the center of gravity. Adjusting weights are included on the feeder to assure passage of the horizontal axis through the combined center of gravity.
Other objects and advantages will become apparent from the following specification taken in connection with the accompanying drawings.
In a highly preferred embodiment, the feeder includes at least one elongated, generally horizontal balance bar as part of the base and which extends generally parallel to the feeding surface. The resilient element or elements are connected between the balance bar and the feeding surface. The balance bar in turn is supported above on underlying surface by generally vertical isolation springs.